NTA Abhyas NEET2020BotanyCell Cycle and Cell DivisionPractice
Prophase-I of meiosis is a long and complex phase in which many events occurs. Arrange the following events of meiosis in the correct sequence and select the correct option. (i) Crossing over (ii) Synapsis (iii) Terminalization of chiasmata (iv) Disappearance of nucleolus
Options
- A(i), (ii), (iii), (iv)
- B(ii), (iii), (iv), (i)
- C(ii), (i), (iv), (iii)
- D(ii), (i), (iii), (iv)
Correct answer
D. (ii), (i), (iii), (iv)
Step-by-step solution
Prophase I of meiosis has been divided into five substages which occur in the sequence as: Leptotene, Zygotene, Pachytene, Diplotene and Diakinesis. Synapsis i.e., pairing of homologous chromosomes occurs during zygotene. Crossing over i.e., exchange of chromatid segments occurs during pachytene. Terminalization of chiasmata i.e., shifting of chiasmata towards the ends of chromosomes and complete disappearance of nucleolus take place during diakinesis.